Fire agate. Agate is a microcrystalline variety of the mineral quartz (silicon oxide). Most agates occur as nodules in volcanic rocks where cavities were filled by silica-rich solutions. As the solutions evaporated,silica deposits built up in regular layers upon the walls. The presence of impurities in the layers can produce a wide range of colours and patterns. The brilliant,iridescent appearance of fire agate is thought to arise from alternating layers (Schiller layers) of silica and iron oxide | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 5100 px × 3425 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |